class Cleanser{
    private String s = "Cleanser";
    public void append(String a){ s += a;}
    public void dilute(){append(" dilute()");}
    public void apply(){append(" apply()");}
    public void scrub(){append(" scrub()");}
    @Override public String toString(){return s;}
    public static void main(String[] args) {
        Cleanser x = new Cleanser();
        x.dilute();x.apply();x.scrub();
        System.out.println(x);
    }
}

public class Detergent extends Cleanser {
    @Override public void scrub(){
        append("Detergent.scrub()");
        super.scrub();
    }
    public void foam(){
        append(" foam()");
    }
    public static void main(String[] args) {
        Detergent x = new Detergent();
        x.dilute();
        x.apply();
        x.scrub();
        x.foam();
        System.out.println(x);
        System.out.println("Testing base class:");
        Cleanser.main(args);
    }
}
